Bob Dylan, Neil Young, Grandmaster Flash and Rage Against the Machine produced era-defining political songs in earlier decades. The '00s gave us Britney Spears.

The '60s gave us "Blowin' in the Wind," folk-poet Bob Dylan's challenge to the brutal status quo. The '70s served up Neil Young's "Ohio," an anthem of generational rage against the military-industrial machine. The '80s laid down "The Message," Grandmaster Flash's hip-hop jeremiad about the vicious cycle of race-based poverty. The '90s broke loose with Rage Against the Machine's "Bulls on Parade," a rap-rock rant targeting corporate greed and cultural imperialism.

And the '00s? It's produced some memorably sardonic screeds (Green Day's "American Idiot"), patriotic hell-yeah's out of Nashville like Toby Keith's "Courtesy of the Red, White & Blue (The Angry American)," and dirges of quiet desperation emanating from "The Suburbs," courtesy of Arcade Fire.

But much of the music that has topped the Billboard charts in the new millennium — Britney, Lil Wayne, Lady Gaga — might suggest that America has been one big party since 2001, despite the Sept. 11 terrorist attacks, two major wars, a wobbly economy and a bitterly divided government. Likewise, the recent popular manifestations of that unrest, the tea party and Occupy Wall Street movements, so far seem to have been largely lost on popular music.

That has left some artists, music industry professionals and listeners pondering how well today's music is serving the restless masses and capturing the essence of times that indeed are a-changin'.

In recent weeks, the Occupy movement has attracted a small number of musician-activists as supporters. Yet many of the high-profile artists who've been speaking out for the 99% — including Lou Reed and Sonic Youth — started their careers decades ago. And although the movement's first benefit CD, "Occupy This Album," will feature David Crosby and Graham Nash, Jackson Brown, Devo, Lloyd Cole, the Guthrie Family and Lucinda Williams, it has yet to enlist a top-grossing act of the last decade.

Crosby, who performed a five-song set at the Occupy Wall Street encampment in November in New York's Zuccotti Park with his longtime friend and collaborator Nash, said that engaging with social issues is something he learned about from folk icons like Pete Seeger and Woody Guthrie. "We are supposed to be the town crier, the troubadour who carries the news from town to town," said Crosby of his role as an artist. Weighing in on issues, he said, is "part of our job."

Hip-hop mogul Russell Simmons also was among the handful of celebrity supporters, including musicians, who regularly visited Zuccotti Park. "There's not been a lot of political [music] in the last 10 years" said Simmons, co-founder of Def Jam Records. "I'm more concerned with what they're going to do now," he added. "There are seeds of a revolution that've just been planted, brand new."

But if there is a revolution rising beneath the radar, will it be televised or podcast? And what will its soundtrack be? Countless new mediums and means of distribution may make it easier to get your music out there but harder to push one cohesive message. And sophisticated modern technology may be put to trivial uses.

"I think there is a certain kind of apathy in our modern times that's really hard to combat," said Eddie Vedder, lead singer of Pearl Jam. "Even with social media — in some parts of the world it's used as a really powerful tool for revolution. Here, it's a powerful tool that people are using to avoid dealing with their own lives. It's a big campfire of gossip."

The relation between political action and peoples' daily lives also has grown murkier, said rapper-producer Lupe Fiasco (a.k.a. Wasalu Muhammad Jaco), in part because today there's no single, focused cause like the Vietnam War or the civil rights movement to galvanize public opinion.

"Politics is probably a little less understood these days, so it's hard to make a song about it," said Jaco, who has rapped about social inequality and has appeared at various Occupy camps over the last few months. In previous eras, he continued, "you could see some type of political action directly affect you within a short period of time," whereas today "a lot of the politics is super-technical."

A number of cultural observers say that today's shrinking record industry seems more hesitant to sign acts that may create more waves than revenue.

"The music that's being released by the major recording labels is [less political], sure," said Robeson Taj P. Frazier, an assistant professor at USC Annenberg's School for Communication. "They're focused on a profit incentive; which in some ways forces them to take on a narrow outlook."

But, Frazier continued, "that's not representative of all the music that people who are organizing now are listening to and what's impacting their consciousness. Youth engagement and interaction through social media allows [consumers] to have access to music that's not limited to being produced and distributed by major record labels."